JP2020139946A - Scan unit for scanning angle scale and angle measuring device having the same - Google Patents

Abstract

To provide a scan unit for scanning an angle scale, and an angle measuring device having the scan unit.SOLUTION: A scan unit 1 includes: a substrates 1.4 having a first surface; a detector 1.1 for generating a signal which depends on the position of an angle; and an evaluation electronic apparatus 1.2 including an electronic part. The electronic part of the evaluation electronic apparatus is surrounded by a casting compound 1.5, and the scan unit includes an electric interface 1.3 for establishing a connection from the evaluation electronic apparatus to a subsequent electronic apparatus. The detector, the electronic part, and the electronic interface are arranged on a first surface 1.41 of the substrate. The electronic part and the electronic interface are located further away from the shaft A of rotation than the detector is. The casting compound is arranged around the first surface of the substrate to the shaft of rotation.SELECTED DRAWING: Figure 1

Description

Angle measuring devices are used, for example, in rotary encoders for determining the angular positions of two mechanical parts that are rotatable relative to each other.
In the scanning unit of the induction angle measuring device, the exciting winding and the receiving winding in the shape of the conductor path are often adhered to a common substrate such as a circuit board fixedly connected to the stator of the encoder. .. There is another component facing the substrate, and a conductive surface as a periodically spaced split structure is adhered to this component as an angle scale, and the conductive surface is a rotary encoder. It is connected to the rotor of the rotary. When an exciting magnetic field is applied to the exciting winding, a signal corresponding to the angular position is generated in the receiving winding or the receiving coil during the relative rotation between the rotor and the stator. These signals are then further processed in the evaluation electronic device.

As a general rule, an angle measuring device having an integrated bearing and an angle measuring device not having an integrated bearing (hereinafter referred to as a bearingless angle measuring device) are distinguished from each other. Angle measuring devices with integrated bearings typically have relatively small rolling bearings, so member groups that are rotatable relative to each other, especially scanning units and angle scales, are the corresponding angle measuring devices. They are located relative to each other at their defined axial and radial positions within. On the other hand, in the case of a bearingless angle measuring device for mounting on a machine such as an (electric) motor, the members that can rotate with respect to each other are fixed at the correct position, especially with the correct axial distance with respect to each other. You need to be careful. Since the machine or motor in question generates heat frequently during operation, it is advantageous that the angle measuring device, especially the scanning unit, be configured so that its components are not exposed to excessive temperature.

EP3355032A1 describes an angle measuring device having a support substrate, and an electronic device for evaluating a detector signal is arranged on the substrate side facing the detector.

EP3355032A1

An underlying task of the present invention is to produce a scanning unit that is economically manufacturable and has advantages in its mounting.

According to the present invention, this problem is solved by the feature of claim 1.
According to it, the present invention includes a scanning unit for an angle measuring device for scanning an angle scale, and as a result, a relative angular position between the scanning unit and the angle scale is defined around an axis of rotation. Can be done. The scanning unit includes a substrate having a first surface. In addition, the scanning unit includes at least one detector suitable for generating signals that depend on the angular position. The scanning unit also includes an evaluation electronic device that includes a plurality of electronic components that are electrically connected to at least one detector to evaluate the signal. In addition, the electronic components of the evaluation electronics are surrounded by a casting compound. In addition, the scanning unit includes an electrical interface for establishing a connection from the evaluation electronics to subsequent electronics. The at least one detector, the electronic component, and the electrical interface are arranged on the first surface of the substrate. The electronic components and the electrical interface are arranged so that they are positioned further away from the axis of rotation than at least one detector. Since the cast compound is arranged around the first surface of the substrate with respect to the rotation axis, in particular, the electronic component and the electrical interface are arranged axially inward with respect to the cast compound. ing.

Angle-dependent signals are, in particular, signals that include information about the relative angular position between the angular scale and the scanning unit.
The term electrical interface should be understood as a conductive connection between a plurality of conductive members that are in direct contact, that is, in contact with each other. This can be, for example, a plug-in device or an electrical coupling device such as a direct cable connection.

The expression that the casting compound is arranged around the axis of rotation means that the casting compound is arranged around the axis by 360 ° in a closed state, for example. Similarly, this expression can also mean the open placement of the cast compound by the orbiting segment, in which case the cast compound is approximately 270 °, 180 °, or 120 ° around the axis. It is arranged around. Similarly, the expression also includes an arrangement in which the casting compound is intermittently arranged around the axis by 360 °.

The cast compound is configured in a ring or ring shape, in particular as a ring consisting of one ring segment or a plurality of ring segments, eg, a closed, open or intermittent ring.

The substrate preferably has a thickness of at least 0.5 mm. In particular, the substrate can not only function as a support for detectors, evaluation electronics, and interfaces, but can also be configured as a mechanical support element. In particular, in this aspect, the substrate can have a metal layer having a thickness of at least 0.5 mm, so that the metal layer functions as a supporting element. At the same time, the substrate thus constructed can dissipate heat relatively well, especially from the area of the evaluation electronic device.

The substrate is configured to be advantageously flat, i.e. not curved.
In a further embodiment of the invention, the substrate has a second surface that is located opposite the first surface, with electronic components and / or interfaces and / or detectors on the second surface. Not placed. In particular, the second surface may be a substantially flat or substantially smooth surface. For example, the second surface of the substrate can simultaneously function as a housing portion or part of the outer surface of the motor housing.

The scanning unit is advantageously configured to operate on an inductive principle. In particular, in this case, the detector is configured as at least one receiving winding.
In a further embodiment of the invention, the scanning unit has at least one exciting winding located on the first surface of the substrate.

The substrate advantageously has at least one mounting element located radially outward of the sealing element. For example, the mounting element can be configured as a hole or clip. The sealing element can be, for example, an O-ring or seal cord vulcanized onto the substrate.

The substrate advantageously has an edge region extending radially outward of the casting compound. In particular, since the edge region extends around the casting compound without interruption, the edge region of the substrate is radially outside the entire casting compound. In particular, the substrate can have at least one mounting element located in the edge region.

According to a further aspect, the invention includes an angle measuring device comprising a scanning unit and an angle scale, the angle scale being rotatably arranged around or around a rotation axis relative to the scanning unit. The relative angular position between the scanning unit and the angular scale is measurable or measurable. Here, the scanning units are arranged so as to be axially offset relative to the angular scale.

The angular scale is advantageously located radially inside the casting compound. In particular, since the axial deviation of the casting compound with respect to the axial stretching is very small, the casting compound is arranged radially outside the angular scale. That is, the angular scale axially enters the (air) volume enclosed by the casting compound.

According to a further aspect of the present invention, the angle measuring device is configured as a guided angle measuring device.
In a further embodiment of the invention, the angular scale has a conductive surface as a split structure at regular or periodic intervals.

The angular scales are advantageously formed, made or manufactured of a conductive material having irregularities as a split structure at regular or periodic intervals. These arrangements can be used, especially when the scanning unit operates by the induction principle.

The angle measuring device is advantageously configured without bearings.
Induction angle measuring devices are often configured so that the angle scale can be scanned by a scanning unit or receiving winding over much of its surroundings and thus can generate angle dependent signals. Alternatively, the angle measuring device can be configured such that the angle scale is scanned by a plurality of scanning points distributed over the entire circumference.

An advantageous form of the present invention is described in the dependent claims.
Further details and advantages of the scanning unit according to the present invention can be seen in the following description of an embodiment with reference to the accompanying drawings.

It is a top view of the scanning unit. It is a detailed view of a scanning unit. It is sectional drawing of a scanning unit. It is sectional drawing of the angle measuring apparatus provided with a scanning unit. It is a top view of the angle measuring device.

The drawing shows an embodiment for a scanning unit 1 in an angle measuring device for scanning an angle scale 2 (see, eg, FIG. 4), the rotation between the scanning unit 1 and the angle scale 2. The relative angular position around the axis A can be determined by the angle measuring device. Therefore, the scanning unit 1 particularly comprises a substrate 1.4 (see FIG. 2) having a first surface 1.41 and a second surface 1.42 inevitably opposed to the first surface 1.41. Including. In addition, the substantially flat, square substrate 1.4 of the presented embodiment also has a relatively solid metal layer 1.44, which here is 1.0 mm thick. Has d. On the metal layer 1.44, there is an electrically insulating layer or a dielectric layer 1.45 configured as, for example, a polyimide layer such as a lacquer or a film. The dielectric layer 1.45 is thinner than the metal layer 1.44 and has a thickness of 20 μm in the presented examples. Therefore, here, the thickness D of the substrate 1 is 1.02 mm. A conductor path is created on the dielectric layer 1.45.

In the presented embodiment, the scanning unit 1 is based on the induction measurement principle. Therefore, the detector 1.1 arranged on the first surface 1.41 is configured as a plurality of receiving windings 1.11. In addition, a plurality of exciting windings 1.12 are arranged on the first surface 1.41. In the presented embodiment, the receiving winding 1.11 and the exciting winding 1.12 are arranged substantially concentrically around the rotation axis A.

The signal generated by the detector 1.1 is transmitted via the conductor path and can be processed by the evaluation electronic device 1.2. FIG. 5 shows, for example, the electronic component 1.21 of the evaluation electronic device 1.2 mounted in the annular region on the substrate 1.4. Further, an interface 1.3 is mounted on the substrate 1.4, which is configured here as a plug connector or an electrical coupling part, in particular a contact support comprising a plurality of electrical contacts 1.32. It has 1.31 (Fig. 3). Therefore, the connection cable to the subsequent electronic device can be connected to the interface 1.3.

Both the electronic component 1.21 of the evaluation electronics 1.2 and the interface 1.3 or the contact support 1.31 are cast after being mounted on the substrate 1.4 and the ring-shaped note according to FIG. Mold compound 1.5 is produced. In FIG. 5, one segment of the ring-shaped cast compound 1.5 is opened to represent the electronic component 1.21 of the evaluation electronic device 1.2.

In the presented embodiment, within the volume of the cast compound 1.5 in an area not open in the figure, there is an additional electronic component 1.21 of the evaluation electronics 1.2. Therefore, the casting compound 1.5 orbits with respect to the rotation axis A and is arranged on the first surface 1.41 of the substrate 1.4. The inner edge of the casting compound 1.5 and the outer edge of the casting compound 1.5 are configured to be chamfered, and the outer edge of the casting compound 1.5 forms a radial support for the sealing element 1.7. .. In the presented embodiment, the seal element 1.7 is configured as an O-ring. The seal element 1.7 is radially supported with respect to the casting compound 1.5 (FIG. 4).

Alternatively, the outer edge of the casting compound may have an undercut, which holds the O-ring particularly axially.
The angle measuring device includes a scanning unit 1 and an angle scale 2, and the scanning unit 1 and the angle scale 2 are arranged so as to be rotatable relative to each other around the rotation axis A. In order to obtain relative rotational potential, current angle measuring devices are not provided with integrated bearings, i.e. rolling bearings or sliding bearings (bearingless angle measuring devices). Rather, the scanning unit 1 is attached to the first mechanical component and the angle scale 2 is attached to the second mechanical component. Here, the first mechanical component is arranged so as to be rotatable relative to the second mechanical component. The scanning unit 1 and the angle scale 2 are separated by a gap and face each other.

The scanning unit 1 can be attached to the first mechanical component using, for example, a screw connection, using the hole 1.43 to which the insert 1.6 is fixed. The first mechanical component can be, in particular, the housing of the motor. The substrate 1.4 or the metal layer 1.44 can function as a support element and, for example, can simultaneously function as a cover for the motor housing. No electronic components, interfaces or detectors are located on the second surface 1.42, so the second surface 1.42 is suitable as part of the outer surface of the motor.

The housing of the motor can have an orbital wall to which the sealing element 1.7 is pressed.
On the angle scale 2 of the angle measuring device, a shaft 2.1 is mounted rotationally immovably in order to be fixedly attached to, for example, a mechanical shaft or a motor shaft. The angular scale 2 comprises a ring-shaped circuit board in which conductive and non-conductive regions, that is, different conductive regions are provided in a periodic order and in the same dividing step. The angle scale 2 with the shaft 2.1 can often be referred to as a rotor.

The exciting winding 1.12 on the scanning unit 1 generates a uniform alternating magnetic field during the operation of the angle measuring device, which is modulated by the angle scale 2 depending on the angular position or rotation angle of the shaft 2.1. To. In the receiving winding 1.11 which is also on the scanning unit 1, an angle-dependent signal is generated by the modulated electromagnetic field.

In the presented embodiment, the angle measuring device is configured by so-called all-around scanning. That is, in particular, the scanning unit 1 is configured such that the angle scale 2 can be scanned by the scanning unit 1 or the receiving winding 1.11 over almost the entire circumference, and thus an angle-dependent signal can be generated. .. That is, the nearly complete split structure of the angular scale 2 is scanned by the scanning unit 1 in order to obtain a signal containing information on the relative angular position.

The signal thus generated is then fed to the evaluation electronic circuit 1.2 where it is further processed. The signal is controlled in the control unit so that it always has a constant signal amplitude or level.

In the evaluation electronic circuit 1.2, the angular position or position value of the angle scale 2 is determined based on the signal. Also, the angular position and rotational speed of the angular scale 2 are transferred to subsequent electronic devices for further electronic processing.

Claims (15)

A scanning unit (1) for an angle measuring device for scanning an angle scale (2), and as a result, rotating a relative angular position between the scanning unit (1) and the angle scale (2). The scanning unit (1) can be defined around the axis (A).
− A substrate (1.4) having a first surface (1.41) and
-With at least one detector (1.1) for generating a signal that depends on the angular position.
-Including the evaluation electronic device (1.2) including a plurality of electronic components (1.21), the electronic component (1.21) of the evaluation electronic device (1.2) is a casting compound (1.5). ), The scanning unit (1) is also surrounded by.
-Includes an electrical interface (1.3) for establishing a connection from the evaluation electronics (1.2) to subsequent electronics.
The at least one detector (1.1), the electronic component (1.21), and the electrical interface (1.3) are the first surface (1.) of the substrate (1.4). 41) Located on the top
The electronic component (1.21) and the electrical interface (1.3) appear to be positioned further away from the axis of rotation (A) than the at least one detector (1.1). Is located in
The casting compound (1.5) is arranged around the rotation axis (A) on the first surface (1.41) of the substrate (1.4). .. In the scanning unit (1) according to claim 1,
A scanning unit in which the substrate (1.4) has a thickness (D) of at least 0.5 mm. In the scanning unit (1) according to claim 2.
A scanning unit in which the substrate (1.4) has a metal layer (1.44) and the metal layer (1.44) has a thickness (d) of at least 0.5 mm. In the scanning unit (1) according to any one of claims 1 to 3.
The substrate (1.4) has a second surface (1.42) arranged to face the first surface (1.41), and the second surface (1.42). A scanning unit in which no electronic component (1.21) is arranged. In the scanning unit (1) according to any one of claims 1 to 4.
A scanning unit in which the detector (1.1) is configured as at least one receiving winding (1.11). In the scanning unit (1) according to claim 5.
A scanning unit in which the scanning unit (1) has at least one exciting winding (1.12) located on the first surface (1.41) of the substrate (1.4). In the scanning unit (1) according to any one of claims 1 to 6.
A scanning unit in which the substrate (1.4) has at least one mounting element (1.43) located radially outside the sealing element (1.7). In the scanning unit (1) according to any one of claims 1 to 7.
A scanning unit in which the substrate (1.4) has an edge region extending radially outward of the casting compound (1.5). In the scanning unit (1) according to claim 8.
A scanning unit in which the substrate (1.4) has at least one mounting element (1.43) located in the edge region. The angle measuring device including the scanning unit (1) and the angle scale (2) according to claim 1, wherein the angle scale (2) rotates relative to the scanning unit (1). It is rotatably arranged about the axis (A), and the relative angular position between the scanning unit (1) and the angle scale (2) can be measured, and the scanning unit (1) is , An angle measuring device arranged so as to be displaced in the axial direction relative to the angle scale (2). In the angle measuring device according to claim 10,
An angle measuring device in which the angle scale (2) is arranged inside the casting compound (1.5) in the radial direction. In the angle measuring device according to claim 10 or 11.
An angle measuring device in which the angle measuring device is configured as a guided angle measuring device. In the angle measuring device according to any one of claims 10 to 12,
An angle measuring device in which the angle scale (2) has a conductive surface as a divided structure at regular intervals. In the angle measuring device according to any one of claims 10 to 13.
An angle measuring device in which the angle scale (2) is formed of a conductive material and has irregularities as a divided structure at regular intervals. In the angle measuring device according to any one of claims 10 to 14.
An angle measuring device in which the angle measuring device is configured without bearings.

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